DEAR DR. BLONZ: There are a number of weight-loss teas at my drug store, and I was wondering which, if any, are worth consideration. -- S.C., San Jose, California
DEAR S.C.: As a basic concept, consuming liquids with (or before) a meal can help you feel fuller, and can therefore cut down the volume of food you eat. While many claim to have special metabolic powers, "weight-loss teas" usually rely on this most natural phenomenon to accomplish their goal.
Some such products might include herbal diuretics, such as couch grass, buchu, dandelion, uva-ursi and butcher's broom. The taking of a diuretic tea can decrease the total amount of water in the body, which will impact the numbers on the scale. But it is only water you are losing, not excess body fat. What's worse, it tends to be a short-term effect, with the water weight usually returning once the regimen is stopped.
Tea is a great beverage, and we are learning that some of the compounds found in green, black and oolong teas offer health benefits. That should be the motivator for drinking it -- not the promise of weight loss. Dramatic claims of success should be viewed with great skepticism.
One product I recall came in a package that displayed a slim woman on the front. The literature indicated that drinking the tea would facilitate the shedding of unwanted weight, but the product was nothing more than a plain black tea of modest quality. If you looked inside the package, there was a piece of paper that explained that you had to eat less and exercise more for the weight-loss plan to work. What a novel approach.
DEAR DR. BLONZ: Have you written about noncaloric sweeteners such as stevia and sucralose? Some of my friends are concerned about the safety of these sweeteners. -- S.S., Portland, Oregon
DEAR S.S.: Sugar substitutes provide few or no calories and have minimal effect on blood sugar, which is a plus for people with diabetes. Then there is the fact that they do not contribute to tooth decay. But while a sugar-substituted dessert, for example, succeeds in putting fewer calories on the plate, there is no reliable evidence that it works as a weight-loss strategy.
A paper by Richard Mattes in the 2009 American Journal of Clinical Nutrition reported that the addition of noncaloric sweeteners to diets posed no benefit for weight loss, or reduced weight gain, unless accompanied by energy (calorie) restriction.
I refrain from encouraging the consumption of noncaloric sweeteners -- not because they are necessarily dangerous, but because I don't encourage seeking out excessive sweetness. The Berkeley Wellness letter has a simple and straightforward piece on the various options: tinyurl.com/zxwf6zs.
Send questions to: "On Nutrition," Ed Blonz, c/o Universal Uclick, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to firstname.lastname@example.org. Due to the volume of mail, personal replies cannot be provided.